Blackboard-eraser.



No. 879,767. PATENTED FEB. 13,1908.

W. H. HARTLEY. BLAOKBOARD ERASER.

APPLIGATION FILED JUNE 13. 1907.

WILLIAM H. HARTLEY, OF MOUNT PLEASANT, MICHIGAN.

BLACKBOARD-ERASER.

Specification of Letters Patent.

Patented Feb. 18, 1908.

Application filed June 13. 1907- Serial No. 378.822.

To all'whom it may concern:

Be it known that 1, WILLIAM H. HARTLEY, a citizen of the United Statesof America, residin at Mount Pleasant, in the county of Isabe la andState of Michigan, have invented new and useful Improvements inBlackboard-Erasers, of which the following is a specification.

This invention relates to blackboard erasers, and one of the principalobjects of the same is to provide a device of this character which ispractically selfcleaning, and in which a new cleaning surface is alwayspresented to the blackboard whenever required.

Another object of the invention is to provide a self cleaning blackboarderaser in which the cleaning bands are mounted upon rollers andsufliciently spaced apart and provided with means whereby the fineparticles of chalk are removed from the surface of the bands anddeposited into a rece tacle within the eraser at each rotation o theerasing bands.

These and other objects may be attained by means of the constructionillustrated in the accompanying drawing, in which:

Figure 1 is a plan view of the back portion of the blackboard eraserwith the cover removed. Fig. 2 is an underside plan view of the cover.Fig. 3 is a side elevation of the eraser. Fig. 4 is a detail view of oneend of the eraser. Fig. 5 is a transverse section of the same.

- Referring to the drawing for a more particular description of myinvention, the numeral 1 designates the body portion of the eraserconsisting of a box-like receptacle having a bottom 2 and upwardlyextending sides 3, preferably provided with curved'ends 4 and 5. Mountedto rotate between the sides 3 at one end is a roller 6 journaled uponthe ends of screws 7 passing through the sides 3 and into the roller 6.A roller 8 is journaled in the opposite ends of the sides 3 in a slot 9in said sides, said roller provided with projecting bearings ortrunnions 10 sup orted upon spiral springs 11 by means 0 which theroller 8 will yield to the action of the eraser. Placed within thereceptacle 1 is an inner support provided with side flanges 12 whichrest upon the inner wall of the bottom 2, said sup ort having an upperwall 13 provided wit a slot 14 which communicates with the interior ofreceptacle 1. Endless bands 15 of felt or other suitable erasingmaterial are mounted upon the rollers 6 and 8 at each side of the slot14 and at opposite sides of the guide lugs 16. These guide lugs arelocated at the opposite ends of the slot 14 and serve to hold theendless bands 15 at opposite sides of said slot.

A cover 17 is connected to the sides 3 o the eraser in any suitablemanner, as by hinges 18, and provided with a suitable latch or fastener19. On the under surface of the cover 17 a series of inwardlyprojecting, oppositely disposed cleaner blades 20 are secured.

The operation of my invention may be briefly described as follows: Theeraser may be used for erasing crayon marks upon a blackboard by movingthe same sidewise, and whenever a new surface is required an endwisemovement of the eraser will bring a new erasing surface in position foruse, and

as the endless erasing bands 15 pass the cleaning blades 20, the fineparticles of chalk are removed from the bands and deposited through theslot 14 in the receptacle 1, Where they may be discharged at anysuitable time by opening the cover 17.

From the foregoing it will be obvious that a blackboard eraser made inaccordance with my invention is practically self-cleaning and providesfor a clean erasing surface at any time, and prevents fine particles ofchalk from escape around the blackboard.

The device can be manufactured at slight cost, is comparatively simplein construction, and is efficient and convenient for its purpose.

Having thus described the invention, what I claim is:

1. A blackboard eraser comprising a box or receptacle, rollers journaledin said receptacle, endless bands of erasive material mounted on saidrollers, and a cover for said receptacle provided with cleaning bladesto bear upon the surface of the endless bands to remove the fineparticles of chalk and deposit them in said receptacle.

2. A blackboard eraser comprising a receptacle, rollers mounted in thereceptacle, one of said rollers being mounted upon springs, endlesserasive bands mounted on said rollers, and a cover provided with meansfor removing the chalk from the bands.

3. A blackboard eraser comprising a box or receptacle, rollers mountedin said receptacle, endless bands mounted on said rollers, a support'forsaid b'andsi provided with a slot, and a cover provided upon its underside with inwardly projecting, oppositely disposed cleaning blades,substantially as described.

4. In a blackboard eraser, the combination of a boX or receptacle,endless erasive bands mounted to rotate upon the eraser, and means forcleaning said bands at one WILLIAM HQ HARTLEY.

Witnesses:

SAML. W. HOPKINS, I. A. FANOHER.

